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1.  Complete Sequences of Two Plasmids in a blaNDM-1-Positive Klebsiella oxytoca Isolate from Taiwan 
Genetic determinants of a blaNDM-1-positive, multidrug-resistant bacterial isolate that caused active infection was investigated by DNA sequencing. Two plasmids, pKOX_NDM1 and pKOX-R1, were identified for the Klebsiella oxytoca strain E718. Sequence annotation revealed a blaNDM-1 gene in pKOX_NDM1 and two extended-spectrum β-lactamase producers (blaCTX-M-3 and blaSHV-12) and a wide array of resistance genes in pKOX-R1. These findings highlight the difficulty in treating multidrug-resistant bacterial infections and the potential danger of emerging resistant enterobacteria.
PMCID: PMC3719732  PMID: 23752513
3.  Staphylococcal Cassette Chromosome mec in MRSA, Taiwan 
Emerging Infectious Diseases  2007;13(3):494-497.
To determine the predominant staphylococcal cassette chromosome (SCC) mec element in methicillin-resistant Staphylococcus aureus, we typed 190 isolates from a hospital in Taiwan. We found a shift from type IV to type III SCCmec element during 1992–2003, perhaps caused by selective pressure from indiscriminate use of antimicrobial drugs.
PMCID: PMC2725918  PMID: 17552111
Methicillin-resistant Staphylococcus aureus; multilocus sequence typing; SCCmec; dispatch
4.  Detection of SARS-associated Coronavirus in Throat Wash and Saliva in Early Diagnosis 
Emerging Infectious Diseases  2004;10(7):1213-1219.
Early detection of SARS-CoV in throat wash and saliva suggests that these specimens are ideal for SARS diagnosis.
The severe acute respiratory syndrome–associated coronavirus (SARS-CoV) is thought to be transmitted primarily through dispersal of droplets, but little is known about the load of SARS-CoV in oral droplets. We examined oral specimens, including throat wash and saliva, and found large amounts of SARS-CoV RNA in both throat wash (9.58 x 102 to 5.93 x 106 copies/mL) and saliva (7.08 x 103 to 6.38 x 108 copies/mL) from all specimens of 17 consecutive probable SARS case-patients, supporting the possibility of transmission through oral droplets. Immunofluorescence study showed replication of SARS-CoV in the cells derived from throat wash, demonstrating the possibility of developing a convenient antigen detection assay. This finding, with the high detection rate a median of 4 days after disease onset and before the development of lung lesions in four patients, suggests that throat wash and saliva should be included in sample collection guidelines for SARS diagnosis.
PMCID: PMC3323313  PMID: 15324540
severe acute respiratory syndrome; SARS; coronavirus; CoV; Taiwan; perspective
5.  Clinical Manifestations, Laboratory Findings, and Treatment Outcomes of SARS Patients 
Emerging Infectious Diseases  2004;10(5):818-824.
Clinical and laboratory data on severe acute respiratory syndrome (SARS), particularly on the temporal progression of abnormal laboratory findings, are limited. We conducted a prospective study on the clinical, radiologic, and hematologic findings of SARS patients with pneumonia, who were admitted to National Taiwan University Hospital from March 8 to June 15, 2003. Fever was the most frequent initial symptom, followed by cough, myalgia, dyspnea, and diarrhea. Twenty-four patients had various underlying diseases. Most patients had elevated C-reactive protein (CRP) levels and lymphopenia. Other common abnormal laboratory findings included leukopenia, thrombocytopenia, and elevated levels of aminotransferase, lactate dehydrogenase, and creatine kinase. These clinical and laboratory findings were exacerbated in most patients during the second week of disease. The overall case-fatality rate was 19.7%. By multivariate analysis, underlying disease and initial CRP level were predictive of death.
PMCID: PMC3323212  PMID: 15200814
severe acute respiratory syndrome; C-reactive protein; intravenous immunoglobulin
6.  SARS in Hospital Emergency Room 
Emerging Infectious Diseases  2004;10(5):782-788.
Thirty-one cases of severe acute respiratory syndrome (SARS) occurred after exposure in the emergency room at the National Taiwan University Hospital. The index patient was linked to an outbreak at a nearby municipal hospital. Three clusters were identified over a 3-week period. The first cluster (5 patients) and the second cluster (14 patients) occurred among patients, family members, and nursing aids. The third cluster (12 patients) occurred exclusively among healthcare workers. Six healthcare workers had close contact with SARS patients. Six others, with different working patterns, indicated that they did not have contact with a SARS patient. Environmental surveys found 9 of 119 samples of inanimate objects to be positive for SARS coronavirus RNA. These observations indicate that although transmission by direct contact with known SARS patients was responsible for most cases, environmental contamination with the SARS coronavirus may have lead to infection among healthcare workers without documented contact with known hospitalized SARS patients.
PMCID: PMC3323223  PMID: 15200809
Severe acute respiratory syndrome; healthcare workers; environmental contamination; real-time reverse transcriptase–polymerase chain reaction
7.  Early Defervescence and SARS Recovery 
Emerging Infectious Diseases  2004;10(3):544-545.
PMCID: PMC3322783  PMID: 15116707
SARS; atypical presentation; temporary defervescence
8.  High Incidences of Invasive Fungal Infections in Acute Myeloid Leukemia Patients Receiving Induction Chemotherapy without Systemic Antifungal Prophylaxis: A Prospective Observational Study in Taiwan 
PLoS ONE  2015;10(6):e0128410.
Invasive fungal infections (IFIs) is an important complication for acute myeloid leukemia (AML) patients receiving induction chemotherapy. However, the epidemiological information is not clear in Southeastern Asia, an area of potential high incidences of IFIs. To clarify it, we enrolled 298 non-M3 adult AML patients receiving induction chemotherapy without systemic anti-fungal prophylaxis from Jan 2004 to Dec 2009, when we applied a prospective diagnostic and treatment algorithm for IFIs. Their demographic parameters, IFI characters, and treatment outcome were collected for analysis. The median age of these patients was 51 years. Standard induction chemotherapy was used for 246 (82.6%) patients, and 66.8% of patients achieved complete remission (CR) or partial remission. The incidence of all-category IFIs was 34.6% (5.7% proven IFIs, 5.0% probable IFIs and 23.8% possible IFIs). Candida tropicalis was the leading pathogen among yeast, and lower respiratory tract was the most common site for IFIs (75.4%, 80/106). Standard induction chemotherapy and failure to CR were identified as risk factors for IFIs. The presence of IFI in induction independently predicted worse survival (hazard ratio 1.536 (1.100–2.141), p value = 0.012). Even in those who survived from the initial IFI insults after 3 months, the presence of IFIs in induction still predicted a poor long-term survival. This study confirms high incidences of IFIs in Southeastern Asia, and illustrates potential risk factors; poor short-term and long-term outcomes are also demonstrated. This epidemiological information will provide useful perspectives for anti-fungal prophylaxis and treatment for AML patients during induction, so that best chances of cure and survival can be provided.
PMCID: PMC4462587  PMID: 26061179
9.  Risk of Active Tuberculosis in HIV-Infected Patients in Taiwan with Free Access to HIV Care and a Positive T-Spot.TB Test 
PLoS ONE  2015;10(5):e0125260.
Interferon-gamma release assays (IGRAs) have been used to identify individuals at risk for developing active tuberculosis (TB). However, data regarding the risk of TB development in HIV-infected patients testing positive for IGRAs remain sparse in the era of combination antiretroviral therapy.
Between 2011 and 2013, 608 HIV-infected patients without active TB undergoing T-Spot.TB testing were enrolled in this prospective observational study at a university hospital designated for HIV care in Taiwan with a declining TB incidence from 72 per 100,000 population in 2005 to 53 per 100,000 population in 2012. All of the subjects were followed until September 30, 2014. The national TB registry was accessed to identify any TB cases among those lost to follow-up.
T-Spot.TB tested negative in 534 patients (87.8%), positive in 64 patients (10.5%), and indeterminate in 10 patients (1.6%). In multivariate analysis, positive T-Spot.TB was significantly associated with older age (adjusted odds ratio [AOR], 1.172 per 10-year increase; 95% confidence interval [CI], 1.022-1.344, P=0.023), past history of TB (AOR, 13.412; 95% CI, 6.106-29.460, P<0.001), and higher CD4 counts at enrollment (AOR, per 50-cell/μl increase, 1.062; 95% CI, 1.017-1.109, P=0.007). Of the 64 patients testing positive for T-Spot.TB, none received isoniazid preventive therapy and all but 5 received combination antiretroviral therapy at the end of follow-up with the latest CD4 count and plasma HIV RNA load being 592.8 cells/μL and 1.85 log10 copies/mL, respectively. One patient (1.6%) developed active TB after 167 person-years of follow-up (PYFU), resulting in an incidence rate of 0.599 per 100 PFYU. None of the 534 patients testing negative for T-Spot.TB developed TB after 1380 PYFU, nor did the 24 patients with old TB and positive T-Spot.TB tests develop TB after 62.33 PYFU.
The risk of developing active TB in HIV-infected patients with positive T-Spot.TB receiving combination antiretroviral therapy is low in Taiwan where the national TB program has led to a sustained decrease in TB incidence.
PMCID: PMC4418700  PMID: 25938227
10.  Carbapenem-Nonsusceptible Enterobacteriaceae in Taiwan 
PLoS ONE  2015;10(3):e0121668.
A total of 1135 carbapenem-resistant (nonsusceptible) Enterobacteriaceae (CRE) isolates were recovered between November 2010 and July 2012 (517 from 2010-2011 and 618 from 2012) from 4 hospitals in Taiwan. Carbapenemase-producing Enterobacteriaceae (CPE) comprised 5.0% (57 isolates), including 17 KPC-2 (16 Klebsiella pneumoniae and 1 Escherichia coli), 1 NDM-1 (K. oxytoca), 37 IMP-8 (26 Enterobacter cloacae, 4 Citrobacter freundii, 4 Raoultella planticola, 1 K. pneumoniae, 1 E. coli and 1 K. oxytoca), and 2 VIM-1 (1 E. cloacae, 1 E. coli). The KPC-2-positive K. pneumoniae were highly clonal even in isolates from different hospitals, and all were ST11. IMP-8 positive E. cloacae from the same hospitals showed higher similarity in PFGE pattern than those from different hospitals. A total of 518 CRE isolates (45.6%) were positive for blaESBL, while 704 (62.0%) isolates were blaAmpC-positive, 382 (33.6% overall) of which carried both blaESBL and blaAmpC. CTX-M (414, 80.0%) was the most common blaESBL, while DHA (497, 70.6%) and CMY (157, 22.3%) were the most common blaAmpC. Co-carriage of blaESBL and blaAmpC was detected in 31 (54.4%) and 15 (26.3%) of the 57 CPE, respectively. KPC-2 was the most common carbapenemase detected in K. pneumoniae (2.8%), while IMP-8 was the most common in E. cloacae (9.7%). All KPC-2-positive CRE were resistant to all three tested carbapenems. However, fourteen of the 37 IMP-8-positive CRE were susceptible to both imipenem and meropenem in vitro. Intra- and inter-hospital spread of KPC-2-producing K. pneumoniae and IMP-8-producing E. cloacae likely occurred. Although the prevalence of CPE is still low, careful monitoring is urgently needed. Non-susceptibility to ertapenem might need to be considered as one criterion of definition for CRE in areas where IMP type carbapenemase is prevalent.
PMCID: PMC4368706  PMID: 25794144
11.  Nontuberculous Mycobacterial Ocular Infections—Comparing the Clinical and Microbiological Characteristics between Mycobacterium abscessus and Mycobacterium massiliense 
PLoS ONE  2015;10(1):e0116236.
To analyze the clinical characteristics of nontuberculous mycobacterial (NTM) ocular infections and the species-specific in vitro antimicrobial susceptibility.
Material and Methods
In 2000 to 2011 at the National Taiwan University Hospital, multilocus sequencing of rpoB, hsp65 and secA was used to identify NTM isolates from ocular infections. The clinical presentation and treatment outcomes were retrospectively compared between species. Broth microdilution method was used to determine the minimum inhibitory concentrations of amikacin (AMK), clarithromycin (CLA), ciprofloxacin (CPF), levofloxacin (LVF), moxifloxacin (MXF) and gatifloxacin (GAF) against all strains. The activities of antimicrobial combinations were assessed by the checkerboard titration method.
A total of 24 NTM strains (13 Mycobacterium abscessus and 11 Mycobacterium massiliense) were isolated from 13 keratitis, 10 buckle infections, and 1 canaliculitis cases. Clinically, manifestations and outcomes caused by these two species were similar and surgical intervention was necessary for medically unresponsive NTM infection. Microbiologically, 100% of M. abscessus and 90.9% of M. massiliense ocular isolates were susceptible to amikacin but all were resistant to fluoroquinolones. Inducible clarithromycin resistance existed in 69.3% of M. abscessus but not in M. massiliense isolates. None of the AMK-CLA, AMK-MXF, AMK-GAF, CLA-MXF and CLA-GAF combinations showed synergistic or antagonistic effect against both species in vitro.
M. abscessus and M. massiliense are the most commonly identified species for NTM ocular infections in Taiwan. Both species were resistant to fluoroquinolones, susceptible to amikacin, and differ in clarithromycin resistance. Combined antimicrobial treatments showed no interaction in vitro but could be considered in combination with surgical interventions for eradication of this devastating ocular infection.
PMCID: PMC4291221  PMID: 25581038
12.  Daptomycin versus linezolid for treatment of vancomycin-resistant enterococcal bacteremia: systematic review and meta-analysis 
BMC Infectious Diseases  2014;14:687.
Linezolid, which has bacteriostatic activity, is approved for the treatment of vancomycin-resistant enterococci (VRE) infections. Meanwhile, daptomycin exerts bactericidal activity against VRE, but is not approved for the treatment of VRE bacteremia. Only a few studies with small sample sizes have compared the effectiveness of these drugs for treatment of VRE bacteremia.
PubMed, EMBASE, and the Cochrane Library were searched for studies of VRE bacteremia treatment published before January 1, 2014. All studies reporting daptomycin and linezolid treatment outcomes simultaneously were included. The endpoints were mortality and microbiological cure. The adjusted odds ratios (aORs) of mortality in daptomycin- and linezolid-treated patients were extracted if available. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for all outcomes using a random-effects model.
Thirteen studies (532 patients receiving daptomycin, 656 patients receiving linezolid) met the selection criteria. All studies had retrospective cohort designs and relatively small sample sizes. Eight studies compared the aORs of mortality in daptomycin- and linezolid-treated patients. Four studies were published as conference papers and there was significant heterogeneity among these studies (I2 = 63%, p = 0.04). Daptomycin use was not associated with better microbiological cure (daptomycin vs. linezolid, OR: 0.67, 95% CI: 0.42–1.06, p = 0.09). However, mortality was higher in patients receiving daptomycin (OR: 1.43, 95% CI: 1.09–1.86, p = 0.009). Subgroup analysis of studies that reported aORs indicated that daptomycin was associated with higher mortality (OR: 1.59, 95% CI: 1.02–2.50, p = 0.04). There was no evidence of publication bias, but all enrolled studies were retrospective, had small sample sizes, and had substantial limitations.
Although limited data is available, the current meta-analysis shows that linezolid treatment for VRE bacteremia was associated with a lower mortality than daptomycin treatment. However, the results should be interpreted cautiously because of limitations inherent to retrospective studies and the high heterogeneity among studies. A large randomized trial is needed to confirm the present results.
Electronic supplementary material
The online version of this article (doi:10.1186/s12879-014-0687-9) contains supplementary material, which is available to authorized users.
PMCID: PMC4269951  PMID: 25495779
Daptomycin; Linezolid; Meta-analysis; Vancomycin-resistant enterococci
13.  Large Isoform of Mammalian Relative of DnaJ is a Major Determinant of Human Susceptibility to HIV-1 Infection 
EBioMedicine  2014;1(2-3):126-132.
Individual differences in susceptibility to human immunodeficiency virus type 1 (HIV-1) infection have been of interest for decades. We aimed to determine the contribution of large isoform of Mammalian DnaJ (MRJ-L), a HIV-1 Vpr-interacting cellular protein, to this natural variation. Expression of MRJ-L in monocyte-derived macrophages was significantly higher in HIV-infected individuals (n = 31) than their uninfected counterparts (n = 27) (p = 0.009). Fifty male homosexual subjects (20 of them are HIV-1 positive) were further recruited to examine the association between MRJ-L levels and occurrence of HIV infection. Bayesian multiple logistic regression revealed that playing a receptive role and increased levels of MRJ-L in macrophages were two risk factors for HIV-1 infection. A 1% rise in MRJ-L expression was associated with a 1.13 fold (95% CrI 1.06–1.29) increase in odds of contracting HIV-1 infection. Ex vivo experiments revealed that MRJ-L facilitated Vpr-dependent nuclear localization of virus. Infection of macrophage-tropic strain is a critical step in HIV-1 transmission. MRJ-L is a critical factor in this process; hence, subjects with higher macrophage MRJ-L levels are more vulnerable to HIV-1 infection.
•Our results suggest that individuals with high levels of MRJ-L may be more susceptible to HIV-1 infection than individuals with low levels of MRJ-L.•We demonstrated that MRJ-L interacts with HIV-1 Vpr and assists with HIV-1 replication. A rise in MRJ-L levels effectively increases the replication of HIV-1 and a reduction in MRJ-L expression significantly decreases HIV-1 production.•Strategies to lower MRJ-L levels in macrophages may be beneficial in controlling HIV-1 infection.
PMCID: PMC4457413  PMID: 26137520
Human immunodeficiency virus type 1 (HIV-1); Macrophages; Mammalian relative of DnaJ (MRJ); Susceptibility to infection
14.  Antimicrobial susceptibilities of Proteus mirabilis: a longitudinal nationwide study from the Taiwan surveillance of antimicrobial resistance (TSAR) program 
BMC Infectious Diseases  2014;14:486.
Longitudinal nationwide data on antimicrobial susceptibility in Proteus mirabilis from different sources are rare. The effects of the revised Clinical and Laboratory Standards Institute (CLSI) β-lactam breakpoints on susceptibility rates and on detecting extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase-producers in this species are also seldom evaluated. The present study analyzed data from the Taiwan Surveillance of Antimicrobial Resistance program to address these issues.
Isolates were collected biennially between 2002 and 2012 from 25 to 28 hospitals in Taiwan. Minimum inhibitory concentrations (MIC) were determined by reference broth microdilution method. All isolates with aztreonam, ceftazidime, or cefotaxime MIC ≥ 2 mg/L were checked for the presence of ESBL by CLSI confirmatory test and subjected to ESBL and AmpC β-lactamases gene detection by PCR. Univariate and multivariate analyses were performed.
Between 2002 and 2012, a total of 1157 P. mirabilis were studied. Susceptibility to cefotaxime, ceftazidime, and ciprofloxacin decreased significantly during the past decade, from 92.6% to 81.7%, 100% to 95.2%, and 80.1% to 53.8%, respectively (P < 0.01). The revised CLSI breakpoints had significant impact on susceptibility to cefazolin (2009 vs. current breakpoints, 71.9% vs. 0.9%) and imipenem (99.8% vs. 55.1%) (P < 0.001 for both). However, using the 2014 cefazolin breakpoints for urinary tract infections, 81.2% of the urine isolates were susceptible. Susceptibilities of isolates from different specimen types were mostly similar but outpatient isolates were more susceptible than inpatient isolates. The overall prevalence of ESBL- and AmpC- producers was 8.2% and 4.7%, respectively, but AmpC carriage increased significantly over the years (from 0 to 7.0%, P < 0.001). ESBL and AmpC β-lactamase-producers were more likely to be found in elderly and ICU patients. The predominant ESBL and AmpC β-lactamase genes were CTX-M- and CMY- types, respectively.
A significant decrease in susceptibility to 3rd-generation cephalosporins and ciprofloxacin occurred in P. mirabilis from Taiwan in the past decade. The prevalence of ESBL remained stable but AmpC β-lactamase-producing P. mirabilis increased significantly. Cefotaxime was a better surrogate than ceftazidime for predicting the presence of these β-lactamases. Continuous surveillance on antimicrobial resistance and associated resistance mechanisms in P. mirabilis is warranted.
PMCID: PMC4162950  PMID: 25192738
Drug resistance; Extended-spectrum β-lactamase; AmpC β-lactamase; Proteus mirabilis; Clinical and Laboratory Standards Institute (CLSI)
15.  Two distinct Do-Not-Resuscitate protocols leaving less to the imagination: an observational study using propensity score matching 
BMC Medicine  2014;12:146.
Do-Not-Resuscitate (DNR) patients tend to receive less medical care after the order is written. To provide a clearer approach, the Ohio Department of Health adopted the Do-Not-Resuscitate law in 1998, indicating two distinct protocols of DNR orders that allow DNR patients to choose the medical care: DNR Comfort Care (DNRCC), implying DNRCC patients receive only comfort care after the order is written; and DNR Comfort Care-Arrest (DNRCC-Arrest), implying that DNRCC-Arrest patients are eligible to receive aggressive interventions until cardiac or respiratory arrest. The aim of this study was to examine the medical care provided to patients with these two distinct protocols of DNR orders.
Data were collected from August 2002 to December 2005 at a medical intensive care unit in a university-affiliated teaching hospital. In total, 188 DNRCC-Arrest patients, 88 DNRCC patients, and 2,051 non-DNR patients were included. Propensity score matching using multivariate logistic regression was used to balance the confounding variables between the 188 DNRCC-Arrest and 2,051 non-DNR patients, and between the 88 DNRCC and 2,051 non-DNR patients. The daily cost of intensive care unit (ICU) stay, the daily cost of hospital stay, the daily discretionary cost of ICU stay, six aggressive interventions, and three comfort care measures were used to indicate the medical care patients received. The association of each continuous variable and categorical variable with having a DNR order written was analyzed using Student’s t-test and the χ2 test, respectively. The six aggressive interventions and three comfort care measures performed before and after the order was initiated were compared using McNemar’s test.
DNRCC patients received significantly fewer aggressive interventions and more comfort care after the order was initiated. By contrast, for DNRCC-Arrest patients, the six aggressive interventions provided were not significantly decreased, but the three comfort care measures were significantly increased after the order was initiated. In addition, the three medical costs were not significantly different between DNRCC and non-DNR patients, or between DNRCC-Arrest and non-DNR patients.
When medical care provided to DNR patients is clearly indicated, healthcare professionals will provide the medical care determined by patient/surrogate decision-makers and healthcare professionals, rather than blindly decreasing medical care.
Electronic supplementary material
The online version of this article (doi:10.1186/s12916-014-0146-x) contains supplementary material, which is available to authorized users.
PMCID: PMC4156651  PMID: 25175307
Medical care; Cardiopulmonary resuscitation; Do-Not-Resuscitate
16.  Epidemiology and Molecular Characterization of Macrolide-Resistant Streptococcus pyogenes in Taiwan 
Journal of Clinical Microbiology  2014;52(2):508-516.
Our multicenter nationwide surveillance data indicated that erythromycin (ERY) resistance among group A Streptococcus (GAS) isolates in Taiwan declined from 53.1% in 1998 and 2000 to 14.6% in 2002 and 2004 and 10.7% in 2006 to 2010 (P < 0.01). The present study aimed to assess the epidemiology of GAS in Taiwan and identify factors associated with ERY resistance. All 127 ERY-resistant (ERYr) isolates and 128 randomly selected ERY-susceptible (ERYs) isolates recovered from 1998 to 2010 were emm typed. ERYr isolates were also characterized by ERY resistance phenotype and mechanisms and pulsed-field gel electrophoresis (PFGE). Multilocus sequence typing was performed on selected ERYr isolates. The predominant emm types in ERYr isolates were emm22 (n = 33, 26.0%), emm12 (n = 24, 18.9%), emm4 (n = 21, 16.5%), and emm106 (n = 15, 11.8%). In ERYs isolates, emm12 (n = 27, 21.9%), emm1 (n = 18, 14.1%), emm106 (n = 16, 12.5%), and emm11 (n = 9, 7.1%) predominated. The most common ERY resistance phenotype was the M phenotype (resistant to macrolides) (70.9%), with all but one isolate carrying mef(A), followed by the constitutive macrolide-lincosamide-streptogramin B resistance (cMLSB) phenotype (26.8%), with isolates carrying erm(B) or erm(TR). ERYr isolates of the emm12-sequence type 36 (ST36) lineage with the cMLSB phenotype were mostly present before 2004, while those of the emm22-ST46 lineage with the M phenotype predominated in later years. Recovery from respiratory (throat swab) specimens was an independent factor associated with ERY resistance. emm1 and emm11 GAS isolates were significantly associated with ERYs, while emm22 was detected only in ERYr GAS. In addition, emm106 isolates were prevalent among the abscess/pus isolates, whereas emm12 isolates were strongly associated with a respiratory (throat) origin. In addition to identifying factors associated with ERY resistance in GAS, our study provides helpful information on the changing GAS epidemiology in Taiwan.
PMCID: PMC3911310  PMID: 24478481
17.  Differential Impact of Resistance-Associated Mutations to Protease Inhibitors and Nonnucleoside Reverse Transcriptase Inhibitors on HIV-1 Replication Capacity 
AIDS Research and Human Retroviruses  2013;29(8):1117-1122.
The effects of drug resistance on HIV-1 replication capacity have been studied, but data from clinical isolates are few. We accessed the patients with HIV-1 infection at the National Taiwan University Hospital who experienced virological failure. Genotypic susceptibility and replication capacity of clinical HIV-1 isolates were measured. There were 80 patients enrolled between September 2007 and August 2010. The HIV-1 replication capacity declined significantly with the increasing number of major resistance-associated mutations (RAMs) to protease inhibitors (PIs) (p<0.001); however, it did not decline significantly with the increasing RAMs to first-line nonnucleoside analogue reverse transcriptase inhibitors (NNRTIs) (p=0.098). Regarding the effects of resistance to antiretroviral drugs in salvage therapy, decreased replication capacity was noted with the increasing RAMs to darunavir/ritonavir (p<0.001) and specific RAMs (L100I, K101P, and Y181C/I/V) to etravirine (p<0.001). Although NNRTI-related RAMs have less remarkable effects, both PI- and NNRTI-related RAMs reduced replication capacity, especially RAMs to darunavir/ritonavir and etravirine, which are commonly used in salvage therapy for treatment of patients infected with highly resistant HIV. Thus, decreased viral fitness during the emergence of RAMs suggests the importance of continued optimal antiretroviral treatment even when virological failure was noted.
PMCID: PMC3715794  PMID: 23594266
18.  Significant social events and increasing use of life-sustaining treatment: trend analysis using extracorporeal membrane oxygenation as an example 
BMC Medical Ethics  2014;15:21.
Most studies have examined the outcomes of patients supported by extracorporeal membrane oxygenation as a life-sustaining treatment. It is unclear whether significant social events are associated with the use of life-sustaining treatment. This study aimed to compare the trend of extracorporeal membrane oxygenation use in Taiwan with that in the world, and to examine the influence of significant social events on the trend of extracorporeal membrane oxygenation use in Taiwan.
Taiwan’s extracorporeal membrane oxygenation uses from 2000 to 2009 were collected from National Health Insurance Research Dataset. The number of the worldwide extracorporeal membrane oxygenation cases was mainly estimated using Extracorporeal Life Support Registry Report International Summary July 2012. The trend of Taiwan’s crude annual incidence rate of extracorporeal membrane oxygenation use was compared with that of the rest of the world. Each trend of extracorporeal membrane oxygenation use was examined using joinpoint regression.
The measurement was the crude annual incidence rate of extracorporeal membrane oxygenation use. Each of the Taiwan’s crude annual incidence rates was much higher than the worldwide one in the same year. Both the trends of Taiwan’s and worldwide crude annual incidence rates have significantly increased since 2000. Joinpoint regression selected the model of the Taiwan’s trend with one joinpoint in 2006 as the best-fitted model, implying that the significant social events in 2006 were significantly associated with the trend change of extracorporeal membrane oxygenation use following 2006. In addition, significantly social events highlighted by the media are more likely to be associated with the increase of extracorporeal membrane oxygenation use than being fully covered by National Health Insurance.
Significant social events, such as a well-known person’s successful extracorporeal membrane oxygenation use highlighted by the mass media, are associated with the use of life-sustaining treatment such as extracorporeal membrane oxygenation.
PMCID: PMC3975881  PMID: 24592981
Life-sustaining treatment; Extra-corporeal membrane oxygenation; Cardiopulmonary resuscitation; Media; Trend
19.  Effectiveness of tigecycline-based versus colistin- based therapy for treatment of pneumonia caused by multidrug-resistant Acinetobacter baumannii in a critical setting: a matched cohort analysis 
BMC Infectious Diseases  2014;14:102.
Colistin and tigecycline have both been shown good in vitro activity among multi-drug resistant Acinetobacter baumannii (MDRAB). A comparative study of colistin versus tigecycline for MDRAB pneumonia is lacking.
The study enrolled adults with MDRAB pneumonia admitted to intensive care units at a referral medical center during 2009–2010. Since there were no standardized minimum inhibitory concentration (MIC) interpretation criteria of tigecycline against A. baumannii, MIC of tigecycline was not routinely tested at our hospital. During the study periods, MIC of colistin was not routinely tested also. We consider both colistin and tigecycline as definite treatments of MDRAB pneumonia. Patients who received tigecycline were selected as potential controls for those who had received colistin. We performed a propensity score analysis, by considering the criteria of age, gender, underlying diseases, and disease severity, in order to match and equalize potential prognostic factors and severity in the two groups.
A total of 294 adults with MDRAB pneumonia were enrolled, including 119 who received colistin and 175 who received tigecycline. We matched 84 adults who received colistin with an equal number of controls who received tigecycline. The two well matched cohorts share similar characteristics: the propensity scores are colistin: 0.37 vs. tigecycline: 0.37, (P = .97); baseline creatinine (1.70 vs. 1.81, P = .50), and the APACHE II score (21.6 vs. 22.0, P = .99). The tigecycline group has an excess mortality of 16.7% (60.7% vs. 44%, 95% confidence interval 0.9% – 32.4%, P = .04). The excess mortality of tigecycline is significant only among those with MIC >2 μg/mL (10/12 vs. 37/84, P = .01), but not for those with MIC ≦ 2 μg/mL (4/10 vs. 37/84, P = .81).
Our data disfavors the use of tigecycline-based treatment in treating MDRAB pneumonia when tigecycline and colistin susceptibilities are unknown, since choosing tigecycline-based treatment might result in higher mortality. The excess mortality of tigecycline-based group may be related to higher MIC of tigecycline (> 2 μg/mL). Choosing tigecycline empirically for treating MDRAB pneumonia in the critical setting should be cautious.
PMCID: PMC3936940  PMID: 24564226
Acinetobacter baumannii; Pneumonia; Colistin; Tigecycline; Mortality; Nephrotoxicity
20.  Serologic response to primary vaccination with 7-valent pneumococcal conjugate vaccine is better than with 23-valent pneumococcal polysaccharide vaccine in HIV-infected patients in the era of combination antiretroviral therapy 
Objectives: The objectives of this study were to compare the serologic responses at week 48 to primary vaccination with 23-valent pneumococcal polysaccharide vaccine (PPV) vs. 7-valent pneumococcal conjugate vaccine (PCV); and to identify factors associated with serologic response in HIV-infected adult patients with access to combination antiretroviral therapy (cART).
Methods: One hundred and four CD4-matched pairs of HIV-infected patients who underwent primary pneumococcal vaccination with 23-valent PPV or 7-valent PCV were enrolled for determinations of anti-capsular antibody responses against four serotypes (6B, 14, 19F and 23F) at baseline, 24 weeks and 48 weeks following vaccination. Significant antibody responses were defined as 2-fold or greater increase of antibody levels at week 48 compared with baseline. The logistic regression model was used to determine the factors associated with serologic response to at least one and two serotypes.
Results: At week 48, patients who received PCV demonstrated a statistically significantly higher response rate to at least 2 serotypes than those who received PPV (37.5% vs. 20.2%, p = 0.006). In multivariate analysis, factors associated with significant antibody responses to at least one or two serotypes included receipt of PCV (adjusted odds ratio [AOR], 2.42 [95% CI, 1.23–4.78] and 3.58 [95% CI. 1.76–7.28], respectively), and undetectable plasma HIV RNA load (< 400 copies/ml) at vaccination (AOR, 1.47 [95% CI, 0.60–3.64] and 3.62 [95% CI, 1.11–11.81], respectively).
Conclusions: Primary vaccination with 7-valent PCV achieved a significantly better serologic responses to one or two out of the four serotypes studied at week 48 than with 23-valent PPV in HIV-infected patients in the cART era. Suppression of HIV replication when primary vaccination was administered was associated with better serologic responses.
PMCID: PMC3859763  PMID: 23291936
Streptococcus pneumoniae; pneumococcal conjugate vaccine; pneumococcal polysaccharide vaccine; HIV infection; immunogenicity; combination antiretroviral therapy
21.  Slow immunological progression in HIV-1 CRF07_BC-infected injecting drug users 
Human immunodeficiency virus type 1 (HIV-1) circulating recombinant form (CRF) 07_BC has caused serious HIV-1 epidemics among injecting drug users (IDUs) in East Asia. Little is known about the characteristics of the virus and its impact on disease progression among the infected individuals. In this study, we compared immunological progression between 423 IDUs infected with CRF07_BC and 194 men who have sex with men (MSM) with primary subtype B infection, and a representative full-length CRF07_BC molecular clone, pCRF07_BC, was constructed to characterize the virus. We found that IDUs infected with CRF07_BC had significantly slower immunological progression in the Cox proportional hazards model (hazard ratio: 0.30; 95% confidence interval: 0.13–0.69; P=0.004). The constructed recombinant CRF07_BC viruses had a reduced processing of the Gag/Gag-Pol polyproteins, a decreased incorporation of Vpr in the virus particle, tethering of virus particles on the plasma membrane and decreased virus growth kinetics. These phenotypes are related to the unique 7-amino acid deletion in the p6 of CRF07_BC, since complementation of the 7-amino acid in pCRF07_BC could improve the defective phenotypes. In summary, compared with MSM infected with HIV-1 subtype B, IDUs infected with CRF07_BC had slower immunological progression, which is likely correlated with interference of virus particle maturation by the 7-amino acid deletion in p6.
PMCID: PMC3880871  PMID: 26038447
disease progression; growth kinetics; HIV subtype; injecting drug use; men who have sex with men; primary HIV infection
22.  Excess Mortality and Long-Term Disability from Healthcare-Associated Staphylococcus aureus Infections: A Population-Based Matched Cohort Study 
PLoS ONE  2013;8(8):e71055.
Staphylococcus aureus is a leading cause of healthcare-associated infections (HAIs), but the impact of S. aureus HAIs on the long-term survival and functional status of hospitalized patients remain unknown. This study aimed to examine whether S. aureus HAIs increase the risks for long-term mortality and disability.
We conducted a retrospective population-based matched cohort study of inpatients at 8 medical centers, 43 regional hospitals, and 63 local hospitals which participated in the Taiwan Nosocomial Infection Surveillance (TNIS). We individually matched 3070 patients with S. aureus HAIs to 6140 inpatients without HAIs at a 1∶2 ratio by age, gender, hospital, specialty, underlying diseases, and the length of stay before onset of the S. aureus HAI. Main outcome measures are one-year excess risks for mortality, new-onset chronic ventilator dependence, and new-onset dialysis-dependent end-stage renal disease.
We found that patients with S. aureus HAIs had an excess one-year mortality of 20.2% compared with matched uninfected inpatients (P<0.001). The excess risk for new-onset chronic ventilator dependence and dialysis-dependent end-stage renal disease was 7.3% and 2.6%, respectively (Ps<0.001). S. aureus HAIs were also associated with an excess hospital stay of 12 days and an extra cost of $5978 (Ps<0.001).
S. aureus HAIs have substantial negative effect on the long-term outcome of hospitalized patients in terms of both mortality and disability, which should be taken into consideration in future cost-effectiveness studies of the control and prevention interventions for S. aureus HAIs.
PMCID: PMC3735502  PMID: 23940689
23.  Clinical and Microbiological Characteristics of Perianal Infections in Adult Patients with Acute Leukemia 
PLoS ONE  2013;8(4):e60624.
Perianal infection is a common problem for patients with acute leukemia. However, neutropenia and bleeding tendency are relatively contraindicated to surgical intervention. The epidemiology, microbiology, clinical manifestations and outcomes of perianal infection in leukemic patients are also rarely discussed.
The medical records of 1102 adult patients with acute leukemia at a tertiary medical center in Taiwan between 2001 and 2010 were retrospectively reviewed and analyzed.
The prevalence of perianal infection was 6.7% (74 of 1102) in adult patients with acute leukemia. Twenty-three (31%) of the 74 patients had recurrent episodes of perianal infections. Patients with acute myeloid leukemia had higher recurrent rates than acute lymphoblastic leukemia patients (p = 0.028). More than half (n = 61, 53%) of the perianal infections were caused by gram-negative bacilli, followed by gram-positive cocci (n = 36, 31%), anaerobes (n = 18, 15%) and Candida (n = 1, 1%) from pus culture. Eighteen patients experienced bacteremia (n = 24) or candidemia (n = 1). Overall 41 (68%) of 60 patients had polymicrobial infection. Escherichia coli (25%) was the most common micro-organism isolated, followed by Enterococcus species (22%), Klebsiella pneumoniae (13%), and Bacteroides species (11%). Twenty-five (34%) of 74 patients received surgical intervention. Acute leukemia patients with surgically managed anal fistulas tended to have fewer recurrences (p = 0.067). Four (5%) patients died within 30 days after diagnosis of perianal infection. Univariate analysis of 30-day survival revealed the elderly (≧ 65 years) (p = 0.015) and patients with shock (p<0.001) had worse outcome. Multivariate analysis showed septic shock to be the independent predictive factor of 30-day crude mortality of perianal infections (p = 0.016).
Perianal infections were common and had high recurrence rate in adult patients with acute leukemia. Empirical broad-spectrum antibiotics with anaerobic coverage should be considered. Shock independently predicted 30-day crude mortality. Surgical intervention for perianal infection remains challenging in patients with acute leukemia.
PMCID: PMC3618431  PMID: 23577135
24.  Complete Genome Sequence of Klebsiella oxytoca E718, a New Delhi Metallo-β-Lactamase-1-Producing Nosocomial Strain 
Journal of Bacteriology  2012;194(19):5454.
We report the complete genome sequence of Klebsiella oxytoca E718, a New Delhi metallo-β-lactamase-1 (NDM-1)-producing strain isolated from a renal transplant patient. The genome contains a 6,097,032-bp chromosome and two multidrug resistance plasmids with sizes of 324,906 bp and 110,781 bp.
PMCID: PMC3457199  PMID: 22965083
25.  Safety and efficacy of high-dose daptomycin as salvage therapy for severe gram-positive bacterial sepsis in hospitalized adult patients 
Increasing the dosage of daptomycin may be advantageous in severe infection by enhancing bactericidal activity and pharmacodynamics. However, clinical data on using daptomycin at doses above 6 mg/kg in Asian population are limited.
A retrospective observational cohort study of all hospitalized adult patients treated with daptomycin (> 6 mg/kg) for at least 72 hours was performed in Taiwan.
A total of 67 patients (40 males) with a median age of 57 years received a median dose of 7.61 mg/kg (range, 6.03-11.53 mg/kg) of daptomycin for a median duration of 14 days (range, 3–53 days). Forty-one patients (61.2%) were in intensive care units (ICU). Sites of infections included complicated skin and soft tissue infections (n = 16), catheter-related bacteremia (n = 16), endocarditis (n = 11), primary bacteremia (n = 10), osteomyelitis and septic arthritis (n = 9), and miscellaneous (n = 5). The median Pitt bacteremia score among the 54 (80.6%) patients with bacteremia was 4. The most common pathogen was methicillin-resistant Staphylococcus aureus (n = 38). Fifty-nine patients (88.1%) were treated with daptomycin after glycopepetide use. Overall, 52 (77.6%) patients achieved clinical success. The all-cause mortality rate at 28 day was 35.8%. In multivariate analysis, the significant predictors of in-hospital mortality in 54 bacteremic patients were malignancies (P = 0.01) and ICU stay (P = 0.02). Adverse effects of daptomycin were generally well-tolerated, leading to discontinuation in 3 patients. Daptomycin-related creatine phosphokinase (CPK) elevations were observed in 4 patients, and all received doses > 8 mg/kg.
Treatment with high dose daptomycin as salvage therapy was generally effective and safe in Taiwan. CPK level elevations were more frequent in patients with dose > 8 mg/kg.
PMCID: PMC3571896  PMID: 23379510
Daptomycin; High dose; Creatine phosphokinase; Treatment outcomes

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